This invention, in terms of apparatus, relates to a chisel clamp for being used to provide an anchor point or pulling point when straightening structural frame or body members of an automobile. In terms of method, the invention includes techniques for attaching the chisel clamp, say to the trunk floor of the automobile, to provide a pulling point or anchor point.
When repairing the frame damage of automobiles, it is common to use a power-pull system in which one end of the automobile frame is anchored by attachment to a chain extending to a tie-down point on the ground. A pulling force is applied to the opposite end of the frame from a chain engaged at one end with a hydraulic pulley apparatus and attached at the opposite end to a pulling point on the automobile frame. It is normally a relatively simple matter to find a secure point for attaching a chain to at least the front portion of the automobile frame in preparation for straightening the automobile.
When straightening the rear portions of an automobile frame, body or floor area, it has often been the practice to attach a clamp to a sheet metal lip of the automobile body which protrudes below the rear trunk space. Typically, the clamp is attached to a chain which, in turn, is attached to a hydraulic pulley apparatus for pulling against the clamp's point of attachment to the rear lip of the automobile body. The pulling force is applied against an anchor provided by a separate chain or cable attached to a front frame member and extending to a tie-down point in front of the automobile. The clamp has teeth which bite into the metal lip and provide a good grip for the pulling point when the jaws of the clamp are bolted together.
In recent years, the metal used in many automobile bodies, including the lip below the trunk space, has not been strong enough to withstand being torn or at least pulled out of shape when a pulling force of sufficient magnitude to straighten the body, frame, or floor area is applied via a clamp attached to the automobile body.